Anatomical studies were made on the structural and decorative elements of the wooden ceiling of the 12th century Cappella Palatina in Palermo, Sicily, to identify the timbers used, analyse their likely provenance, and discuss the selection criteria used by the builders. One hundred and fifty fragments were examined. Abies sp., Pinus sp., Betula sp., Populus sp. and Fagus sylvatica were found and all are most probably from Sicily. Some of the Abies fragments probably belong to Abies nebrodensis as they have exceptionally long tracheids, very tall rays, and abundant crystals. This species was over-Iogged in the past and now only 29 trees remain in the Madonie Natural Reserve in Sicily. Abies and Pinus are found in vertieal and horizontal painted panels, while Populus, Betula and Fagus were used in smaller parts of the muqarnas (painted niches). The choice of species seems to have been related to original tree size. The large size of the Abies boles meant that quarter sawn panels could be used. Sieilian Abies was highly valued at that time for its wood quality.Special attention was paid to the problem of distinguishing partly degraded Abies and Cedrus woods. However, the scalloped torus in some sampies displayed ambiguous features and these sampies were therefore classified as Abies/Cedrus.